Coal-drill



J. PASZKO.

COAL DRILL. APPLICATION FILED NOV. 9, 1920- Patented Apr. 26, .921.

FIG.

INVENTOR. rli anz'o BY (fi TORNEY.

UNITED STATES JOHN IPASZKO, OF TAMAROA, ILLINOIS.

COAL-DRILL.

Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed November 9, 1920. Serial No. 422,903.

To all whom it may concern:

Be it known that I, JOHN PASZKO, citizen of the United States ofAmerica, residing at Tamaroa, in the county of Perry and State ofIllinois, have invented certain new and useful Improvements in Coal-Drills, of which the following is a specification.

This invention relates to certain new and useful improvements in coaldrills and has specific reference to the provision of a drill of thischaracter with a novel form of detachable cutter points whereby thelatter may be readily renewed from time to time when damaged or brokenwithout requiring the entire drill to be discarded.

The principal ob'ect of the invention is to provide a coal drill of theusual spiral and rotatable type with outer and inner detachable cutterbits, the bits being so constructed to have the inner bit serve as asecuring means for the outer blts.

Further objects of the invention will become apparent as the nature ofthe invention is better understood and the same consists in the novelform, combination and arrangement of parts hereinafter more fullydescribed in connection with the accompanying drawing, in which likereference characters indicate similar parts throughout the severalviews.

In the drawing, 7

Figure 1 is a fragmentary side elevational View, partly broken away andpartly in vertical section, of a drill constructed in accordance withthe present invention,

Fig. 2 is an elevational view of the lower portion of the drill shown inFig. 1 as seen looking toward the left of Fig. 1,

Fig. 3 is a transverse sectional View taken substantially upon lineIII-III of Fig. 2, and

Fig. 4 is a perspective view of one of the outer cutter bits.

Referring more in detail to the several views, the present inventionembodies a drill body 5 formed spirally in the usual manner and havingthe usual socket 6 in its upper end for reception of the usual tang 7 ofthe link 8 which is employed for rotating said drill body.

The present invention consists in providing the lower end of the drillbody 5 with a plurality of diametrically opposed longitudinal grooves 9open at their lower ends which extend to the lower end of the drill body5. an wh se upper n s rminate in her 13 is rigidly carried by the lowerend of the body 5 by having its threaded shank 14 screwed into the axleopening 15 of said body 5, said opening 15 being in communication withthe transverse opening 10. The upper end of the cutter bit member 13 isprovided with a reduced extension or dowel 16 which projects into theopening 10 between the lugs 12 when said member 13 is properly disposed.The dowel 16 is shaped to snugly fit and enter the space provided by themating concavities or recesses 17 formed in the contiguous faces of thelugs 12, whereby the dowel 16 as an integral part of the member 13performs the function of securing the outer bits 11 in operativeposition.

From the foregoing description, it will be seen that when any of theinitial cutters 11 or 13 become so damaged as to be no longer of value,the same may be readily renewed by threadingthe cutter member 13 out ofthe opening 15 of the body 5. When this has been done, the dowel 16 isremoved from between the lugs 12 so that either one of the cutters 11may be withdrawn for being replaced by a new like cutter. It will alsobe seen that when the device is assembled, a quite rigid construction ispresented as the cutters are well braced against lateral strains andefliciently held against relative movement.

In operation, the cutters 13 and 11 drill into the material in the usualmanner in advance of the body 5 and, efliciently serve the purpose ofboring shot holes or the like when coal is blasted.

Minor changes may be made without departing from the spirit and scope ofthe invention as claimed.

What is claimed as new is:

1. A drill of the class described comprising in combination with aspiral rotatable drill body having a transverse opening adjacent itslower end, a pair of outer cutter blts extending longitudinally of saiddrill,

body at opposite sides thereof and projecting beyond the lower end ofthe same, a pair of lateral lugs rigid with the outer cutter bits andprojecting into said transverse opening in overlapping relation, saidlugs being provided with mating recesses, and an inner cutter bit memberdetachably connected to the lower end of the drill body and providedwith a dowel formed to fit the space provided by said recesses ofthelateral lugs whereby the outer cutter bits are rigidly detachablyfastened in position.

2. A drillof the class described comprising in combination with aspiral. rotatable drill body having a transverse opening adjacentitslower end, a pair of outer cutter bits extending longitudinally of saiddrill body at opposite sides thereof and projecting beyond the lower endof the same, apair of lateral lugs rigid with the outer cutter bits andprojecting into said transverse opening in overlapping relation, saidlugs being provided with mating recesses, and an inner cutter bit memberdetachably connected to the lower end of the drill body and providedwith a dowel formed to lit the space provided by said recesses of thelateral lugs .whereby the outer cutter bits are rigidly detachablyfastened in position, saic drill body being provided with longitudinalgrooves communicating w th said transverse 2 opening and within whichsaid outer cutter bits are snugly fitted, whereby the latter are bracedagainst lateral strains.

3. The combination with'a rotatable drill body having outer cutter bitsupon opposite sides of the lower end thereof, of an inner cutter bitmember detachably carried by said drill body and having meansinterlocking with the outer cutter bits for detachably securing them inposition, said means including laterally recessed lugs upon the outercutter bits arranged in overlapping relation and provided with matingrecesses, and a dowel member carried by the inner cutter bit memberdetachably received within said recesses of said lugs.

4. A drill comprising a drill body having a transverse opening adjacentits lower end and an axial opening communicating with said transverseopening, an inner cutter bit member threaded into said axial opening andhaving a rigid dowel pin projecting intosaid transverse opening, outercutter bits arranged at diametrically opposite sides of said drill bodyat its lower bits arranged at diametrically opposite sides of said drillbody at its lower end and projecting therebeyond, lateral lugs rigidwithsaid outer cutter bitsand projecting within said transverse opening inoverlapping relation, said lugs each partially embracing said;

dowel in whereb the outer; cutter bits are securely fastenedto the drillbody, said drill body being providedwith' longitudinal grooves withinwhich the outer cutter bits are fitted for bracing the latter againstlateral strains. V

In testimony whereofI affix my signature.

. JOHN PASZKO.

